In a 2014 investigation, The Washington Post reported that the FBI had been under-counting fatal police shootings by more than half. An eighteen year-old Michael Brown was killed by police in St. Louis, Missouri, shining a light on the issue of police brutality in the United States. Relying on news, social media, and police reports, the Washington Post compiled a comprehensive list of police shootings from 2015 to 2022 to amend the issue of under-counting police killings of civilians. Police brutality stems from a lack of accountability. The police force is consistently protected from the consequences of violence, regardless of the use of such tools of accountability as police body cameras. We studied the use of body cameras in police shootings to understand whether the use of body cameras was more common in one state over another. More specifically, we asked: within our data set of 6,574 observations of police shootings from 2015 to 2022 in the United States, is there a correlation between the U.S. state of observation and whether a body camera was turned on during the shooting? We found that the use of body cameras during fatal police shootings certainly varies by state, pointing to the conclusion that state policy plays a role in whether body cameras are turned on during active police duty.
This data set includes information on every fatal police shooting from January 1, 2015 to the present. It is updated regularly by the Washington Post. Some of the Post’s key findings from the data set include:
Overall, police nationwide kill approximately 1,000 civilians annually.
Black people are killed by police at a higher rate than White people. In absolute numbers, the White population is killed most often by police. Black people, accounting for less than 13 percent of the population, are killed more than twice the rate of White people.
The majority of victims are male and between the ages of 20 and 40 years.
Police shootings occur in every state. In cities, they are more frequent. The states with the highest rates of shootings (considering state population) are New Mexico, Alaska, and Oklahoma.
These findings are the result of previous research by the Washington Post. One of the data set’s limitations is the absence of data on populations at the time of the observation. This information would be valuable for any type of racial injustice analysis. The research we gathered through the EDA began with very basic analyses:
These basic univariate analyses were created to better understand the data set and to identify any interesting patterns that emerged. We began doing more complex multivariate analyses and noting any interesting findings:
Hover over the map below to see the breakdown of fatal police shootings, divided by the race of the victim. We looked at the total number of deaths in each state by race and following are some of the insights:
We see that the state with the highest level of victims of police violence is California with a total of 885 victims, followed by Texas with a total of 553 and then Florida with 427.
These results are consistent with the populations of these states, with the highest being California, then Texas, and then Florida.
We also observe that the highest number of deaths is for Hispanic people in California, whereas in Texas and Florida there are more fatal shootings of White people.
Then we looked at the age of the suspect shot, as well as their race. We made the following observations:
We see from the boxplot below that the median age for Black people that have been killed by police is 29 years.
White people have a relatively higher median age of 35 years whereas Asian people have the highest median age of around 38 years.
If we look at the age of each victim against the status of their mental health, we can make the following observation: signs of mental illness appear more frequently within the 30s age range while death by police for people age 50 and above are more common for people showing signs of mental illness.
We also looked at the death by race and gender, coming up with the following insight: individuals across all races that were shot and killed by police were more often men.
We then looked at the distribution of deaths by race and the top 5 armed categories. We discovered that around 9% of the Black victims were unarmed whereas only approximately 6% of the White victims were unarmed. Guns were the most used weapon across all races except for Asian individuals. Asian victims were more often wielding knives.
The following graph illustrates the deaths per year by race from 2015-2022:
We looked at the distribution of deaths by suspects’ race and whether they were trying to flee or not. The following are some of our most interesting observations:
Only 53% of Black victims shot were not fleeing whereas 71% of the Asian victims who were shot were not trying to flee.
The car is the most popular method of fleeing among White victims whereas for Black victims, the most popular method of fleeing was by foot.
After performing all of this exploratory data analysis, we decided we wanted to ask a state- and region-based question. Performing a more comparative analysis using this data set could help us understand why police shootings occur in some states over others. This required us to divide the data in a new way. For data visualization purposes, we chose to divide each state into regions. However, our main focus will rely on state-by-state comparative analysis. The following regional subsets include:
| Northwest (NW) | Southwest (SW) | Midwest (MW) | Southeast (SE) | Northeast (NE) |
|---|---|---|---|---|
| California | New Mexico | Illinois | Georgia | New York |
| Washington | Arizona | Wisconsin | Alabama | Rhode Island |
| Oregon | Texas | Indiana | Mississippi | Maryland |
| Nevada | Oklahoma | Michigan | Louisiana | Vermont |
| Idaho | Hawaii | Minnesota | Tennessee | Pennsylvania |
| Utah | - | Missouri | North Carolina | Maine |
| Montana | - | Iowa | South Carolina | New Hampshire |
| Colorado | - | Kansas | Florida | New Jersey |
| Wyoming | - | North Dakota | Arkansas | Connecticut |
| Arkansas | - | South Dakota | West Virginia | Massachusetts |
| Arkansas | - | Nebraska | DC | - |
| - | - | Ohio | Virginia | - |
Fatal shootings in the Northwest United States:
## [1] 1810Fatal shootings in the Southwest United States:
## [1] 1226Fatal shootings in the Midwest United States:
## [1] 1080Fatal shootings in the Southeast United States:
## [1] 1890Fatal shootings in the Northeast United States:
## [1] 568After dividing up the data set, we decided to spotlight the body camera variable. This column in the csv file asked whether the body camera was turned on or off during the fatal police shooting. The data was compiled from official police records, completed by the officers on site. In the Washington Post’s brief article introducing the data set and examining some of the most interesting findings, there was no mention of the body camera variable. This provided us an opportunity to create a relevant, meaningful research project on a little-studied aspect of police work. Our final research question is as follows:
Within our data set of 6,574 observations of police shootings from 2015 to 2022 in the United States, is there a correlation between the U.S. state of observation and whether a body camera was turned on during the shooting?
After performing the technical analysis needed to assert that body camera use varies by state, there is still valuable information we need to find a link between state policy on body cameras and the rate at which body cameras are turned on during fatal shootings. The remainder of this paper will attempt to bridge quantitative analysis using the Washington Post data set with qualitative information on state body camera policy. We will also look into funding by state for police work to see if there is a strong correlation between the amount of police funding and the rate at which body cameras are turned on during fatal shootings.
Number of fatal shootings where the body camera was on:
## body_camera n
## 1 TRUE 947Number of fatal shootings where the body camera was off:
## body_camera n
## 1 FALSE 5627We created some figures to visualize body camera use by state and region. In the below bar graph, TRUE signifies a police body camera that was on, while FALSE indicates the body camera was off:
A very important variable allowed us to study body camera use variation by state. This variable is stbcp, or the proportion of shootings when a police body camera was turned on by state. We first checked our data for normality. Because the plot below is relatively linear, we concluded this data is close enough to normality for our purposes.
This scatter plot below illustrates the comparative power of stbcp. Each point on the graph depicts a state’s proportion of shootings where the police body camera was turned on during the incident. These data points also show an interesting regional variation. For example, we can see that there is very little variation in Southwest, and many differences among states in the Midwest.
We performed a chi-square test to understand whether there is a significant difference between the proportions of body cameras being on during fatal shootings each state.
\(H_{0}\): There is no significant differences between US States in the proportion of body cameras being turned on during police shootings
\(H_{A}\): There is a significant difference between US State in the proportion of body cameras being turned on during police shootings
Significance Level: \(\alpha = 0.05"\)
## Min. 1st Qu. Median Mean 3rd Qu. Max.
## 0.000 0.101 0.133 0.144 0.183 0.409##
## Pearson's Chi-squared test
##
## data: contable
## X-squared = 3e+05, df = 2300, p-value <2e-16With a p-value of less 2e-16, we easily pass our significance level of alpha=0.05 and have shown that there exists significant differences between different states’ proportions of body camera usage during fatal police shootings. The challenge now becomes, what is causing this variation in state use of body cameras during active police work? We intend to delve into the reasons why there are differences and research what factors may explain these differences between states. This will require understanding state laws and policies regarding the use of police body cameras. We must also understand the police force consequences for turning off body cameras during police activity in different states.
Studying the use of body cameras in police work is an important topic of study for data-driven policy research in the United States. We hope to be able to apply this correlation between the U.S. state of observation and whether the body camera was on or off during the shooting to state policy on body cameras during police work.
We have the visualization, as well as the Chi-square test, to confirm that there is a significant difference in stbcp (the proportion of shootings when a police body camera was turned on by state). Let us now look at the rankings by state of stbcp, from most to least likely of having a body camera on during a police shooting.
| State | stbcp | State | stbcp | State | stbcp |
|---|---|---|---|---|---|
| DC | 0.409 | Vermont | 0.333 | Nevada | 0.330 |
| Utah | 0.307 | Maryland | 0.277 | Connecticut | 0.238 |
| Iowa | 0.225 | Hawaii | 0.212 | Nebraska | 0.200 |
| Rhode Island | 0.200 | California | 0.188 | Idaho | 0.185 |
| Indiana | 0.185 | Oklahoma | 0.179 | Arizona | 0.161 |
| Alabama | 0.160 | New York | 0.160 | New Mexico | 0.159 |
| South Carolina | 0.156 | New Hampshire | 0.150 | Illinois | 0.148 |
| Wisconsin | 0.146 | Virginia | 0.144 | North Dakota | 0.143 |
| North Carolina | 0.134 | Michigan | 0.133 | Minnesota | 0.133 |
| Ohio | 0.131 | Texas | 0.131 | Kansas | 0.130 |
| Delaware | 0.125 | Colorado | 0.123 | Louisiana | 0.119 |
| Washington | 0.103 | Kentucky | 0.103 | Tennessee | 0.101 |
| Montana | 0.100 | New Jersey | 0.100 | Florida | 0.0995 |
| Georgia | 0.0988 | Alaska | 0.0952 | Arkansas | 0.0787 |
| Oregon | 0.069 | West Virginia | 0.0678 | South Dakota | 0.0625 |
| Missouri | 0.037 | Pennsylvania | 0.0352 | Maine | 0.000 |
| Wyoming | 0.000 |
Here we can see that the states with the highest number of observations where the police body camera was turned on include DC, Vermont, and Nevada. The states with the lowest number include Pennsylvania, Maine, and Wyoming–Maine and Wyoming having no recorded police shooting where a body camera was turned on. Let us now do a deep-dive into state policy on body cameras for these six states.
The four most common state laws that govern body camera usage will guide our analysis of individual state policy. These laws are as follows:
Either a study group or pilot program on the use of body-worn cameras was used or was recommended by law.
Laws dictate where, when, and how, body cameras can be used during police activity.
The public has access to police footage.
There is a prescribed amount of time videos are stored before being discarded.
Although there are other laws which apply to body cameras, these are the four major laws specific to their use. We hypothesize that the applications of these laws will line up well with the stbcp scores we see for each state. We will also include information on the amount of money spent on policing per capita each state.
DC stbcp score:
## [1] 0.409While DC does not have any requirement for a study group or pilot program, it does possess the three other laws. Before being issued a body camera, officers are required to be trained in their use. The only situation in which a police officer is prohibited from turning on his body camera is when engaging with students and minors. The 2015 Body-Worn Camera Program Amendment Act allows the mayor to release police footage for cases of public interest. The act also gives the police up to 40 days to respond to all Freedom of Information requests from the public to hand over footage (which of course police can respond that the footage is inaccessible). Finally, the police may retain footage for no more than 90 days unless the recordings serve as evidence.
DC spends $965 per capita on policing, the highest of any state in the United States by about double. This likely provides DC police with ample funds for police body cameras and their required training.
Vermont stbcp score:
## [1] 0.333Unlike in DC, Vermont did require its State Law Enforcement Advisory Board to produce a report using research methods like study groups to recommend procedures for the use of body cameras, storage time, and exemptions for the Public Records Act. However, there is still no law set in place which governs where and when police may use or not use their body cameras. Vermont’s Law Enforcement Advisory Board Model Policy states that open records requests apply to all body camera recordings. If disputes arise between a public requester and the police department, the recording will be maintained until the dispute is settled. Finally, Vermont has very strict laws for the erasure of police recording. Only with permission from the State Archivist or under law can police body camera footage be erased.
Vermont ranks very low on police spending with only $351 per capita put towards policing.
Nevada stbcp score:
## [1] 0.33Similar to DC, Nevada has no legal requirement for a study group or pilot program like Vermont does. It does have pretty strict laws on the use of body cameras during active police work. Any officer who is frequently out in the field must be equipped with a body camera while on duty. Under law, the officer is required to turn on the camera when responding to a call or engaging in any confrontation between the police and the public. Under Nev.Rev.Stat. § 289.830, the camera may not be turned off until the investigation is complete. Any recording is subject to a public records request, but is only approved to be released on a case-by-case basis. The only requirement for video storage is that all recordings must be saved for at least fifteen days since the time of the incident.
Nevada spends $477 per capita on policing. Among the 50 states plus DC, it ranks second in the best allocation of police resources, only behind Florida.
Pennsylvania stbcp score:
## [1] 0.0352Pennsylvania requires municipalities to establish their own written policies regarding training on the proper use of body cameras, when the body cameras should be turned on, and all protocols for disciplinary conduct when such policies are violated. There is no state law governing how, where, and when body cameras are used. Civilians may request access to footage, and police are given 30 days from the time they recieve the request to either fulfill or deny it. However, all recordings containing evidence, information regarding a criminal charge, or confidential victim information are exempt from public requests. Footage is only saved if there is an active public request for it or it provides evidentiary value.
Pennsylvania spends $335 per capita on policing, which is the lowest we have seen in this analysis thus far.
Maine stbcp score:
## [1] 0Maine has zero laws governing the use of body cameras. In 2021, the Maine State Police began the process of allocating funds for the introduction of body cameras in police work. Its stbcp is 0 simply because police do not use body cameras at all.
The state spends only $244 per capita on policing. Again, this is the lowest amount of money spent on policing we have seen.
Wyoming stbcp score:
## [1] 0Wyoming’s sole law on access to police recordings is to prohibit public access except to the person in the recording. Officers are equipped with body cameras as of 2021.
The state spends $400 per capita on policing. Both Wyoming and Maine are ranked close to last on policing allocation of funds.
If we are comparing the top 3 states for stbcp with the worst 3 states, as we have above, clearly there is a trend showing that rigorous state policy and funding corresponds with higher rates of body cameras turned on during fatal shootings. Now let’s look at all states in relation to these four laws governing the use of body cameras and state funding for policing.
| State | stbcp | How many of the 4 laws does the state possess? | Police funding per capita |
|---|---|---|---|
| DC | 0.409 | 3 | $965 |
| Vermont | 0.333 | 3 | $351 |
| Nevada | 0.330 | 3 | $477 |
| Utah | 0.307 | 3 | $289 |
| Maryland | 0.277 | 4 | $503 |
| Connecticut | 0.238 | 3 | $363 |
| Iowa | 0.225 | 0 | $290 |
| Hawaii | 0.212 | 1 | $384 |
| Nebraska | 0.200 | 4 | $302 |
| Rhode Island | 0.200 | 0 | $485 |
| California | 0.188 | 4 | $564 |
| Idaho | 0.185 | 1 | $302 |
| Indiana | 0.185 | 3 | $238 |
| Oklahoma | 0.212 | 2 | $288 |
| Arizona | 0.161 | 1 | $401 |
| Alabama | 0.160 | 0 | $296 |
| New York | 0.160 | 3 | $570 |
| New Mexico | 0.159 | 3 | $365 |
| South Carolina | 0.156 | 2 | $275 |
| New Hampshire | 0.150 | 4 | $362 |
| Illinois | 0.148 | 1 | $448 |
| Wisconsin | 0.146 | 3 | $330 |
| Virginia | 0.144 | 4 | $316 |
| North Dakota | 0.143 | 1 | $337 |
| North Carolina | 0.134 | 2 | $345 |
| Michigan | 0.133 | 2 | $293 |
| Minnesota | 0.133 | 2 | $428 |
| Ohio | 0.131 | 4 | $347 |
| Texas | 0.131 | 3 | $323 |
| Kansas | 0.130 | 1 | $363 |
| Delaware | 0.125 | 4 | $401 |
| Colorado | 0.123 | 3 | $402 |
| Louisiana | 0.119 | 2 | $326 |
| Washington | 0.103 | 4 | $334 |
| Kentucky | 0.103 | 1 | $183 |
| Tennessee | 0.101 | 1 | $335 |
| Montana | 0.100 | 0 | $350 |
| New Jersey | 0.100 | 3 | $449 |
| Florida | 0.0995 | 3 | $470 |
| Georgia | 0.0988 | 3 | $287 |
| Alaska | 0.0952 | 0 | $555 |
| Arkansas | 0.0787 | 2 | $244 |
| Oregon | 0.069 | 3 | $376 |
| West Virginia | 0.0678 | 0 | $254 |
| South Dakota | 0.0625 | 1 | $259 |
| Missouri | 0.037 | 1 | $321 |
| Pennsylvania | 0.0352 | 3 | $335 |
| Maine | 0.000 | 0 | $244 |
| Wyoming | 0.000 | 1 | $400 |
While there does seem to be a trend of higher stbcp scores for states with more laws on body cameras and more funding for policing, we would need to perform more technical analysis to assert causality. Looking at the six case studies (DC, Vermont, Nevada, Pennsylvania, Maine, and Wyoming), we can easily see that more strict body camera laws and higher funding for policing correspond with the three states with the highest stbcp scores. However, when we look further into the list, we see states like Iowa with 0 laws governing body camera use but with a relatively high stbcp score. Before we can determine that state policy in DC, Vermont, and Nevada should be used as a model for body camera policy, more research is needed to consider all factors that may contribute to body cameras being turned on during a fatal shooting.
Studying the use of body cameras in police work is an important topic of study for data-driven policy research in the United States. We hope to be able to apply this correlation between the U.S. state of observation and whether the body camera was on or off during the shooting to state policy on body cameras. The relevancy of studying fatal shootings cannot be understated in the field of U.S. public policy. One limitation of this EDA is the lack of research on racial injustice and proportionality in fatal shootings by race. This will be an important facet of our future research if we continue to pursue this research topic.
1,032 people have been shot and killed by police in the past year (November 10, 2022), The Washington Post. https://www.washingtonpost.com/graphics/investigations/police-shootings-database/
N.G. La Vigne, M. ulle, N. Erondu, D. Lawrence, L. Robin, T. Meko, B. Chartoff, D. Wood, Police Body-Worn Camera Legislation Tracker (July 14, 2022), The Urban Institute. https://apps.urban.org/features/body-camera-update/
J. Michtom, US Budget Analysis: Policing and Corrections Spending by State (October 21, 2022), Money Geek. https://www.moneygeek.com/living/state-policing-corrections-spending/
Wyoming Police Now Equipped with Body Cameras (February 19, 2021), What’s Up Wyoming. https://www.whatsupwyoming.com/2021/02/wyoming-police-now-equipped-with-body-cameras/
What is the Status of Body Cameras in Maine? A Closer Look at the State’s Laws (2021) Gov QA. https://www.govqa.com/status-of-body-cameras-in-maine/